JP2009123618A - Organic el display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display device in which a second electrode is deposited so that the whole surface of a film pattern using an inorganic material can be covered and as a result a film surface and end portion of the inorganic layer does not react with oxygen and moisture and a display failure does not occur since a dark spot is not created and durability can be improved; and to provide its manufacturing method. <P>SOLUTION: The organic EL display device includes a substrate, a plurality of first electrodes formed on the substrate, a plurality of partition walls for dividing the first electrode into different pixels, an inorganic layer containing hole-transporting layer formed on the first electrodes, an organic light-emitting layer formed on the hole-transporting layer, and a second electrode covering the whole surface of the hole-transporting layer formed on the organic light-emitting layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic EL display device and a method for manufacturing the same, and in particular, by forming a second electrode so as to cover the entire surface of a film pattern using an inorganic material, an organic EL display device free from display defects, and The present invention relates to an organic EL display device capable of improving the durability of the organic EL display device and a manufacturing method thereof.

  An organic EL element is an element in which an organic light emitting layer made of an organic light emitting material is formed between two opposing electrodes, and light is emitted by passing a current through the organic light emitting layer. The thickness of the organic light emitting layer is important for production. In order to make a color display using this, it is necessary to pattern with high definition.

  Organic light-emitting materials that form the organic light-emitting layer include low-molecular materials and high-molecular materials. Generally, low-molecular materials are formed into a thin film by vacuum deposition or the like, and then patterned using a fine pattern mask. However, this method has a problem that the larger the substrate is, the less the patterning accuracy is. In addition, since the film is formed in a vacuum, there is a problem that the throughput is poor.

  Therefore, recently, a method in which a polymer material is dissolved in a solvent to form a coating solution and a thin film is formed by a wet coating method has been tried. In the case of forming an organic light emitting medium layer including an organic light emitting layer by a wet coating method using a coating material of a polymer material, the layer structure is generally a two-layer structure in which a hole transport layer and an organic light emitting layer are laminated from the anode side. Is. At this time, the organic light emitting layer is formed by dissolving or stably dispersing organic light emitting materials having respective emission colors of red (R), green (G), and blue (B) in a solvent in order to form a color panel. It is necessary to paint with organic luminescent ink.

  However, since the materials other than the light emitting material are generally not separately applied, it is sufficient to form a solid film as a common layer for all colors, and there is no need for high-definition patterning. Therefore, as a hole transport layer, a polymer is formed by a wet coating method, a low molecular organic material is formed by a vacuum evaporation method, an inorganic substance is formed by a vacuum evaporation method, a sputtering method, a CVD method (chemical vapor deposition method), The film is formed by other film forming methods. Among these, particularly in the case of inorganic substances, there is a problem that the composition ratio and the structure are changed by being dissolved in water or being oxidized.

  Although the adverse effect is reduced by sealing the device (organic EL element) under an inert gas in an environment in which the amount of moisture and oxygen are strictly controlled, the residual moisture and oxygen in the gas However, it was insufficient because it reacted and a non-light emitting region called a dark spot was formed. In particular, the reaction has reached the display area from a portion not covered with another film.

  Patent Document 1 discloses a technique using a metal oxide as an inorganic material.

  As shown in FIG. 6, a conventional organic EL display device 400 includes, for example, an inorganic hole transport layer 33, an organic light emitting layer (not shown), a counter electrode on a display region 30 provided with a plurality of pixel electrodes 31. 32 is formed. Among these, when the hole transport layer 33 made of an inorganic hole transport material is formed on the display region 30, the driver IC installation part, the contact part of the counter electrode 32, the adhesive part of the sealing member, etc. are left. The film is formed into a pattern using a vacuum deposition method, a sputtering method, a CVD method, or the like. Thereafter, the pattern of the counter electrode 32 on which the pattern is formed is different from the pattern of the inorganic hole transport layer 33 or is opposed to prevent the short-circuit between the counter electrode 32 and the pixel electrode 31 disposed on the substrate. The pattern of the hole transport layer 33 may be made larger than the pattern of the counter electrode 32 as an insulating film below the electrode 32. In this case, an uncovered region of the hole transport layer 33 is generated.

As shown in FIG. 7, the film portion of the hole transport layer 33 not covered with the counter electrode 32 reacts with oxygen or moisture 37, and the reaction region reaches the display region 30 at an early stage, which is called a dark spot. It has been found that this causes a non-light emitting part and causes a problem. In particular, it has been found that this problem is remarkable in the material of the inorganic hole transport layer 33 whose EL characteristics are known to be improved.
Japanese Patent No. 2824411

  In the present invention, by forming the second electrode so as to cover the entire pattern surface of the film using the inorganic material, the film surface and the edge of the inorganic layer do not react with oxygen or moisture, and no dark spot is generated. Therefore, it is to provide an organic EL display device capable of improving durability without display defects and a method for manufacturing the same.

  The invention according to claim 1 of the present invention is formed on a substrate, a plurality of first electrodes formed on the substrate, a plurality of partition walls dividing the first electrode into different pixels, and the first electrode. A hole transport layer including an inorganic layer, an organic light emitting layer formed on the hole transport layer, and a second electrode covering the entire surface of the hole transport layer formed on the organic light emitting layer. The organic EL display device is characterized.

  The invention according to claim 2 of the present invention is the organic EL display device according to claim 1, wherein the film thickness of the second electrode is 80 nm or more.

  The invention according to claim 3 of the present invention is the organic EL display device according to claim 1 or 2, wherein the film thickness of the second electrode is equal to or thicker than the film thickness of the inorganic layer.

  The invention according to claim 4 of the present invention is the organic EL display device according to any one of claims 1 to 3, wherein the material of the inorganic layer is a metal oxide.

  The invention according to claim 5 of the present invention is the organic EL display device according to any one of claims 1 to 4, wherein the height of the partition wall is 0.1 μm or more and 10 μm or less.

  According to a sixth aspect of the present invention, a substrate is prepared, a plurality of first electrodes are formed on the substrate, a plurality of partition walls are formed so as to partition the first electrode into different pixels, and the first electrode A hole transport layer including an inorganic layer is formed thereon, an organic light emitting layer is formed on the hole transport layer, and a second electrode is formed on the organic light emitting layer so as to cover the entire surface of the hole transport layer. This is a method for manufacturing an organic EL display device.

  The invention according to claim 7 of the present invention is the method for manufacturing an organic EL display device according to claim 6, wherein the film thickness of the second electrode is 80 nm or more.

  The invention according to claim 8 of the present invention is the method of manufacturing an organic EL display device according to claim 6 or 7, wherein the film thickness of the second electrode is equal to or thicker than the film thickness of the inorganic layer. It is.

  The invention according to claim 9 of the present invention is the method for manufacturing an organic EL display device according to any one of claims 6 to 8, wherein the material of the inorganic layer is a metal oxide.

  The invention according to claim 10 of the present invention is the method of manufacturing an organic EL display device according to any one of claims 6 to 9, wherein the height of the partition wall is 0.1 μm or more and 10 μm or less. It is.

  According to an eleventh aspect of the present invention, at least one of the first electrode, the partition, the hole transport layer, the organic light emitting layer, and the second electrode is formed using a wet film forming method. The method of manufacturing an organic EL display device according to claim 6.

  According to the present invention, by forming the second electrode so as to cover the entire pattern surface of the film using an inorganic material, the film surface and the edge of the inorganic layer do not react with oxygen or moisture, and dark spots are not generated. Since it does not occur, it is possible to provide an organic EL display device and a method for manufacturing the organic EL display device that have no display defect and can improve durability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings referred to in the following description of the embodiments are for explaining the configuration of the present invention, and the size, thickness, dimensions, and the like of each part illustrated are different from the actual ones. The present invention is not limited to these.

  As shown in FIG. 1, an organic EL display device 100 according to an embodiment of the present invention includes a substrate 5 provided with a thin film transistor (hereinafter, simply referred to as “TFT”), and a thin film transistor for each pixel. The pixel electrode 13, the partition wall 14 formed for partitioning each pixel, the hole transport layer 3 including the inorganic layer formed above the pixel electrode 13, and the interface formed on the hole transport layer 3 A layer layer 16, an organic light emitting layer 17 formed on the interlayer layer 16, and a counter electrode 2 formed on the organic light emitting layer 17 so as to cover the entire surface. Here, the hole transport layer 3, the interlayer layer 16, and the organic light emitting layer 17 are referred to as an organic light emitting medium layer 26.

  FIG. 2 is a schematic top view of FIG. 1, and shows the display device 4 having only the inorganic layer among the display area 1, the pixel electrode 13, and the organic light emitting medium layer 26 and having the counter electrode 2.

[Substrate 5]
As shown in FIG. 1, a substrate (back plane) 5 used in the organic EL display device 100 according to the embodiment of the present invention includes a TFT (thin film transistor) and a first electrode (pixel) of the active matrix driving type organic EL display device 100. Electrode) 13 is provided on the substrate 5, and the TFT and the first electrode 13 are electrically connected.

  The TFT and the organic EL display device 100 configured above the TFT are supported by the substrate 5. Any material can be used as the substrate 5 as long as the substrate 5 has mechanical strength and insulation and is excellent in dimensional stability.

  The material of the substrate 5 is, for example, a plastic film or sheet such as glass, quartz, polypropylene, polyethersulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, or these plastics. Metal oxides such as silicon oxide and aluminum oxide on films and sheets, metal fluorides such as aluminum fluoride and magnesium fluoride, metal nitrides such as silicon nitride and aluminum nitride, metal oxynitrides such as silicon oxynitride, Translucent base material with single or laminated polymer resin film such as acrylic resin, epoxy resin, silicone resin, polyester resin, metal foil such as aluminum and stainless steel, sheet, plate, plastic film and sheet Aluminum, copper, nickel, a metal film such as stainless steel or the like can be used non-translucent substrate as a laminate but are not limited to these.

  What is necessary is just to select the translucency of the board | substrate 5 according to which surface light extraction of the organic electroluminescent display apparatus 100 is performed. The substrate 5 made of these materials is subjected to moisture proofing treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to prevent moisture from entering the organic EL display device 100. Preferably there is. In particular, it is preferable to reduce the moisture content and gas permeability coefficient in the substrate 5 in order to avoid the intrusion of moisture into the organic light emitting medium layer 26 (described later).

  As the thin film transistor provided over the substrate 5 according to the embodiment of the present invention, a known thin film transistor can be used. Specifically, a thin film transistor composed mainly of an active layer 6 in which source / drain regions 10 and 12 and a channel region are formed, a gate insulating film 7 and a gate electrode 8 can be mentioned. The structure of the thin film transistor is not particularly limited, and examples thereof include a staggered type, an inverted staggered type, a top gate type, and a coplanar type.

  The active layer 6 is not particularly limited. For example, the active layer 6 is an inorganic semiconductor material such as amorphous silicon, polycrystalline silicon, microcrystalline silicon, cadmium selenide, metal oxide, thiophene oligomer, poly (p-ferri). It can be formed of an organic semiconductor material such as (lenvinylene).

The active layer 6 is formed by, for example, laminating amorphous silicon by plasma CVD and ion doping; forming amorphous silicon by LPCVD (low pressure chemical vapor deposition) using SiH ₄ gas, and by solid phase growth After amorphous silicon is crystallized to obtain polysilicon, ion doping is performed by ion implantation; LPCVD using Si ₂ H ₆ gas, and PECVD (plasma chemical vapor deposition) using SiH ₄ gas Amorphous silicon is formed by a method, annealed by a laser such as an excimer laser, and amorphous silicon is crystallized to obtain polysilicon, followed by ion doping by an ion doping method (low temperature process); low pressure CVD method or LPCVD method Polysilicon is laminated by , Is thermally oxidized to form a gate insulating film at 1000 ° C. or higher, a gate electrode 8 of the n ⁺ polysilicon is formed thereon, then, a method of ion doping (high temperature process), and the like by an ion implantation method.

As the gate insulating film 7 according to the embodiment of the present invention, those normally used as the gate insulating film 7 can be used. For example, SiO ₂ formed by PECVD method, LPCVD method, etc .; polysilicon For example, SiO ₂ obtained by thermally oxidizing the film can be used.

  As the gate electrode 8 according to the embodiment of the present invention, those normally used as the gate electrode 8 can be used, for example, metals such as aluminum and copper; refractory metals such as titanium, tantalum and tungsten Polysilicon, refractory metal silicide, polycide, and the like, but the present invention is not limited thereto.

  The thin film transistor according to the embodiment of the present invention may have a single gate structure, a double gate structure, or a multi-gate structure having three or more gate electrodes. Moreover, you may have a LDD structure and an offset structure. Further, two or more thin film transistors may be arranged in one pixel.

  In the present invention, the thin film transistor needs to be connected so as to function as a switching element of the organic EL display device 100, and the drain electrode 10 of the thin film transistor and the pixel electrode 13 of the organic EL display device 100 are electrically connected.

[Pixel electrode 13]
As shown in FIG. 1, the pixel electrode 13, which is the first electrode according to the embodiment of the present invention, is formed on the substrate 5 and patterned as necessary. The pixel electrode 13 is partitioned by a partition wall 14 and becomes a pixel electrode 13 corresponding to each pixel.

  Examples of the material of the pixel electrode 13 include metal composite oxides such as ITO (indium tin composite oxide), indium zinc composite oxide, and zinc aluminum composite oxide, metal materials such as gold and platinum, these metal oxides, Either a single layer or a laminate of fine particle dispersion films in which fine particles of a metal material are dispersed in an epoxy resin or an acrylic resin can be used, but the present invention is not limited to these.

  When the pixel electrode 13 is used as an anode, it is preferable to select a material having a high work function such as ITO. In the case of a so-called bottom emission structure in which light is extracted from below (substrate 5 side), it is necessary to select a light-transmitting material. If necessary, in order to reduce the wiring resistance of the pixel electrode 13, a metal material such as copper or aluminum may be provided as an auxiliary electrode. Here, in the case of a so-called top emission structure in which light is extracted from above (the direction opposite to the substrate 5 side), the counter electrode 2 can be stacked on the substrate 5.

  As the formation method of the pixel electrode 13, depending on the material, dry film forming methods such as resistance heating vapor deposition method, electron beam vapor deposition method, reactive vapor deposition method, ion plating method, sputtering method, gravure printing method, screen printing, etc. A wet film forming method such as a method can be used, but the present invention is not limited thereto.

  As a patterning method for the pixel electrode 13, an existing patterning method such as a mask vapor deposition method, a photolithography method, a wet etching method, or a dry etching method can be used depending on a material or a film forming method. In the case where a substrate on which a TFT is formed is used as the substrate 5, it is formed so as to be conductive corresponding to the lower pixel.

[Partition 14]
The partition 14 according to the embodiment of the present invention can be formed so as to partition a light emitting region corresponding to each pixel. It is preferable to form the pixel electrode 13 so as to cover the end (see FIG. 1). In general, the active matrix driving type organic EL display device 100 has a pixel electrode 13 formed for each pixel, and each pixel tends to occupy as large an area as possible, so that the end of the pixel electrode 13 is covered. The most preferable shape of the partition 14 to be formed is basically a lattice shape that divides each pixel electrode 13 by the shortest distance.

  As a method for forming the partition wall 14, as in the past, an inorganic film is uniformly formed on a substrate (thin film transistor and pixel electrode 13), masked with a resist, and then dry-etched, or a photosensitive resin is formed on the substrate. Is a method of forming a predetermined pattern by photolithography, but the present invention is not limited thereto. If necessary, a water repellent can be added, or plasma or UV can be irradiated to impart liquid repellency to the ink after formation.

  The preferred height of the partition wall 14 is not less than 0.1 μm and not more than 10 μm, more preferably not less than 0.5 μm and not more than 2 μm. If it is higher than 10 μm, the formation and sealing of the counter electrode 2 is hindered. If it is lower than 0.1 μm, the end of the pixel electrode 13 cannot be covered, or the organic light emitting medium layer 26 is short-circuited or mixed with adjacent pixels when forming the organic light emitting medium layer 26. It is because it will do.

[Organic luminescent medium layer 26]
The organic light emitting medium layer 26 according to the embodiment of the present invention includes the hole transport layer 3, the interlayer layer 16, and the organic light emitting layer 17. In addition to the hole transport layer 3 and the interlayer layer 16, layers such as a hole injection layer, an electron transport layer, and an electron injection layer can be suitably used as the functional layer of the organic light emitting medium layer 26.

After the partition wall 14 is formed, the hole transport layer 3 can be formed. When an inorganic material is used as the hole transport material of the hole transport layer 3 according to the embodiment of the present invention, examples of the inorganic material include Cu ₂ O, Cr ₂ O ₃ , Mn ₂ O ₃ , and FeOx (x˜0. 1), NiO, CoO, Pr ₂ O ₃ , Ag ₂ O, MoO ₂ , Bi ₂ O ₃ , ZnO, TiO ₂ , SnO ₂ , ThO ₂ , V ₂ O ₅ , Nb ₂ O ₅ , Ta ₂ O ₅ , A metal oxide such as MoO ₃ , WO ₃ , or MnO ₂ is formed using a vacuum deposition method, a sputtering method, or a CVD method. However, the material is not limited to these. These metal carbides, nitrides, borides and the like can also be used.

  When an organic layer other than the hole transport layer 3 is used as the inorganic layer, examples of the organic hole transport material for forming the hole transport layer 15 include polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole (PVK) derivatives, and poly (3,4-ethylene. Dioxythiophene) (PEDOT) and the like are exemplified, but the present invention is not limited thereto. These materials are dissolved or dispersed in a solvent, and are formed using various coating methods using a spin coater or the like and letterpress printing methods.

  Here, the hole transport layer 3 may be provided continuously between the plurality of partition walls 14 and between the partition walls 14 as shown in FIG. Alternatively, it may be formed separated by the partition wall 14.

  As shown in FIG. 1, process efficiency can be improved by forming a space between a plurality of partition walls 14 and continuously between the partition walls 14. On the other hand, if it is formed so as to be separated by the partition wall 14, it is possible to reliably prevent charge leakage between the pixels.

  After the formation of the hole transport layer 3, the interlayer layer 16 can be formed. Examples of the material used for the interlayer layer 16 according to the embodiment of the present invention include polyvinyl carbazole or a derivative thereof, a polyarylene derivative having an aromatic amine in a side chain or a main chain, an arylamine derivative, a triphenyldiamine derivative, and the like. Examples thereof include polymers containing a group amine, but the present invention is not limited thereto. These materials are dissolved or dispersed in a solvent, and are formed using various coating methods using a spin coater or the like and letterpress printing methods. When an inorganic material is used as the material of the interlayer layer 16, the metal oxide can be formed using a vacuum deposition method, a sputtering method, or a CVD method. As the inorganic material of the interlayer layer 16, the same inorganic material as that of the hole transport layer 3 can be used.

  After the formation of the interlayer layer 16, the organic light emitting layer 17 can be formed. The organic light emitting layer 17 according to the embodiment of the present invention is a layer that emits light when an electric current is passed, and the organic light emitting material forming the organic light emitting layer 17 is, for example, a coumarin type, a perylene type, a pyran type, an anthrone type, or a porphyrene. , Quinacridone, N, N′-dialkyl-substituted quinacridone, naphthalimide, N, N′-diaryl-substituted pyrrolopyrrole, iridium complex, etc. Examples thereof include those dispersed in molecules, polyarylene-based, polyarylene vinylene-based, and polyfluorene-based polymer materials, but the present invention is not limited to these.

  These organic light emitting materials are dissolved or stably dispersed in a solvent to form an organic light emitting ink. Examples of the solvent for dissolving or dispersing the organic light emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, or a mixed solvent thereof. Among them, aromatic organic solvents such as toluene, xylene, and anisole are preferable from the viewpoint of the solubility of the organic light emitting material. Moreover, surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. may be added to organic luminescent ink as needed.

  FIG. 5 shows a relief printing apparatus 300 for pattern printing of an organic light emitting ink made of an organic light emitting material on a substrate to be printed 24 on which a pixel electrode 13, a partition wall 14, a hole transport layer 3 and an interlayer layer 16 are formed. The schematic diagram of is shown. The relief printing apparatus 300 according to the embodiment of the present invention includes an ink tank 19, an ink chamber 20, an anilox roll 21, and a plate copper 23 on which a plate 22 provided with a relief plate is mounted. The ink tank 19 contains an organic light-emitting ink diluted with a solvent, and the organic light-emitting ink is fed into the ink chamber 20 from the ink tank 19. The anilox roll 21 is instructed to be rotatable in contact with the ink supply part of the ink chamber 20.

  As the anilox roll 21 rotates, the ink layer 211 of the organic light-emitting ink supplied to the surface of the anilox roll 21 is formed with a uniform film thickness. The ink in the ink layer 211 is transferred to the convex portion of the plate 22 mounted on the plate cylinder 23 that is driven to rotate in the vicinity of the anilox roll 21. On the flat table 25, the printing substrate 24 on which the pixel electrode 13 (transparent electrode), the hole transport layer 3, and the interlayer layer 16 are formed is printed on the printing substrate 24 with the ink on the projections of the plate 22. The organic light emitting layer 17 is formed on the substrate 24 to be printed through a drying process as necessary.

[Counter electrode 2]
Next, the counter electrode 2 that is the second electrode according to the embodiment of the present invention can be formed (see FIG. 1). When the counter electrode 2 is used as a cathode, a substance having a high electron injection efficiency into the organic light emitting layer 17 and a low work function can be used.

  A specific material of the counter electrode 2 is a single metal such as Mg, Al, or Yb, or a compound such as Li, oxidized Li, or LiF is sandwiched by about 1 nm at the interface in contact with the organic light emitting medium layer 26. Al or Cu having high conductivity may be laminated and used. Alternatively, in order to achieve both electron injection efficiency and stability, one or more metals such as Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, and Yb having a low work function and stable Ag, An alloy system with a metal element such as Al or Cu may be used. Specifically, alloys such as MgAg, AlLi, and CuLi can be used.

  The formation method of the counter electrode 2 can be a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method depending on the material, but is not limited to these in the present invention. is not.

  FIG. 4A is a schematic cross-sectional view showing an end portion of the organic EL display device 100. By covering the entire surface of the hole transport layer 3 including the inorganic layer with the counter electrode 2, the surface and edges of the inorganic layer do not react with oxygen or moisture 27, so that no dark spots are generated and there is no display defect. Device 100 can be obtained. Furthermore, by making the thickness of the counter electrode 2 equal to or thicker than the thickness of the inorganic layer, the inorganic layer can be completely covered with the material of the counter electrode 2 at the end of the pattern, and the durability of the organic EL display device 100 is improved. Can be improved.

  As shown in FIG. 4B, when the thickness of the counter electrode 2 is made smaller than 80 nm, oxygen and moisture 27 enter and dark spots are generated. Furthermore, when the counter electrode 2 is formed to be thinner than the inorganic layer, oxygen and moisture 27 enter and the durability is lowered.

  In the embodiment of the present invention, the active matrix driving type organic EL display device 100 has been described. However, the present invention relates to the first electrode (pixel electrode 13) and the second electrode (opposing) that sandwich the organic light emitting medium layer 26. The present invention can also be suitably applied to a passive matrix drive organic EL display device 200 in which the electrode 2) is an anode line and a cathode line that intersect each other. For example, as shown in FIG. 3, an active matrix drive organic EL display device 100 is formed by covering the entire surface of a hole transport layer 3 including an inorganic layer provided in stripes with a counter electrode 2 provided thereon. Similar effects can be obtained. FIG. 3 shows only the inorganic layer of the organic light emitting medium layer 26.

[Sealed body]
The organic EL display device 100 can emit light by sandwiching a light emitting material between electrodes (between the pixel electrode 13 and the counter electrode 2) and passing an electric current. However, the organic light emitting material is caused by moisture or oxygen in the atmosphere. Since it easily deteriorates, a sealing body for shielding from the outside can usually be provided (not shown). The sealing body can be manufactured, for example, by providing a resin layer on a sealing material.

The sealing material needs to be a base material having low moisture and oxygen permeability. Examples of the material of the sealing material include ceramics such as alumina (aluminum oxide), silicon nitride, and boron nitride, glass such as alkali-free glass and alkali glass, quartz, and moisture resistant film. However, it is not limited to these. Examples of moisture-resistant films include films formed by CVD of SiOx on both sides of plastic substrates, films with low permeability and water-absorbing films, or polymer films coated with a water-absorbing agent. The water vapor transmission rate is preferably 10 ⁻⁶ g / m ² / day or less.

  Examples of the material for the resin layer include a photo-curing adhesive resin, a thermosetting adhesive resin, a two-component curable adhesive resin, and an ethylene ethyl acrylate (EEA) made of epoxy resin, acrylic resin, silicone resin, etc. Examples thereof include acrylic resins such as polymers, vinyl resins such as ethylene vinyl acetate (EVA), thermoplastic resins such as polyamide and synthetic rubber, and thermoplastic adhesive resins such as acid-modified products of polyethylene and polypropylene.

  Examples of methods for forming a resin layer on a sealing material include solvent solution method, extrusion lamination method, melting / hot melt method, calendar method, nozzle coating method, screen printing method, vacuum laminating method, hot roll laminating method, etc. The present invention is not limited to these examples. A material having a hygroscopic property or an oxygen absorbing property may be contained as necessary. The thickness of the resin layer formed on the sealing material is arbitrarily determined depending on the size and shape of the organic EL display device 100 to be sealed, but is preferably about 5 μm to 500 μm. In addition, although it formed as a resin layer on a sealing material here, it can also form directly in the organic EL display apparatus 100 side.

  Finally, the organic EL display device 100 and the sealing body are bonded together in a sealing chamber. When the sealing body has a two-layer structure of a sealing material and a resin layer, and a thermoplastic resin is used for the resin layer, it is preferable to perform only pressure bonding with a heated roll.

  When a thermosetting adhesive resin is used, it is preferable to perform heat curing at a curing temperature after pressure bonding with a heated roll. In the case where a photocurable adhesive resin is used, curing can be performed by further irradiating light after pressure bonding with a roll.

  An active matrix substrate 5 including a thin film transistor functioning as a switching element provided on the substrate 5 and a pixel electrode 13 formed thereabove is used. The size of the substrate 5 is 5 inches diagonal and the number of pixels is 320 × 240.

  A partition wall 14 was formed in such a shape as to cover the end of the pixel electrode 13 provided on the substrate 5 and partition the pixel. The partition wall 14 is formed by using a positive resist made by Nippon Zeon Co., Ltd., a product name “ZWD 6216-6” with a thickness of 2 μm on the entire surface of the substrate 5 by a spin coater method, and then using a photolithography method to a width of 40 μm. The partition wall 14 was formed by patterning. As a result, a pixel area of 960 × 240 dots and a pitch of 0.12 mm × 0.36 mm was defined.

  On the pixel electrode 13, as a hole transport layer 3, molybdenum oxide having a thickness of 50 nm was formed into a pattern by a shadow mask method using a vacuum deposition method. The pattern region was formed using a metal mask having an opening of 120 mm × 100 mm so as to be formed on the entire display region.

  Thereafter, the pixel electrode 13, the partition wall 14 and the hole transport layer formed on the substrate 5 using an ink in which a polyvinyl carbazole derivative, which is a material of the interlayer layer 16, is dissolved in toluene so as to have a concentration of 0.5%. 3 is set as the printing substrate 24 of the relief printing apparatus 300, and the interlayer layer 16 is formed by relief printing in accordance with the line pattern just above the hole transport layer 3 on the pixel electrode 13 sandwiched between the partition walls 14. Printing was done. At this time, 300 lines / inch anilox roll 21 and a water developing type photosensitive resin plate were used. The film thickness of the interlayer layer 16 after printing and drying was 10 nm.

  A pixel electrode 13, partition 14, and hole transport layer formed on the substrate 5 using an organic light-emitting ink in which a polyphenylene vinylene derivative, which is an organic light-emitting material of the organic light-emitting layer 17, is dissolved in toluene to a concentration of 1%. 3 and the interlayer layer 16 are set as the printing substrate 24 of the relief printing apparatus 300, and the organic light emitting layer 17 is printed by the relief printing method in accordance with the line pattern just above the interlayer layer 16 sandwiched between the partition walls 14. Went. At this time, an anilox roll 21 of 150 lines / inch and a water developing type photosensitive resin plate were used. The thickness of the organic light emitting layer 17 after printing and drying was 80 nm.

  Thereafter, a calcium film is formed as a counter electrode 2 by a vacuum evaporation method with a thickness of 20 nm using a metal mask having an opening of 120 mm × 100 mm, and thereafter an aluminum film is used using a metal mask having an opening of 124 mm × 104 mm. The molybdenum oxide film (hole transport layer 3) was formed to a thickness of 150 nm so as to cover the entire surface.

  Thereafter, using a glass plate as a sealing material, it was placed so as to cover the entire light emitting region, and the adhesive was thermally cured at about 90 ° C. for 1 hour for sealing. When the active matrix driving type organic EL display device 100 thus obtained was driven, it was in a uniform light emitting state without luminance unevenness due to the wiring resistance of the counter electrode 2.

  Before the hole transport layer 3 was formed, it was produced in the same procedure as in Example 1, and as the hole transport layer 3, a pattern was formed with a thickness of 40 nm by a shadow mask method using nickel oxide by vacuum evaporation. The pattern region was formed using a metal mask having an opening of 120 mm × 100 mm so as to be formed on the entire display region. Thereafter, the interlayer layer 16 and the organic light emitting layer 17 were produced in the same procedure as in Example 1.

  Thereafter, a calcium film is formed as a counter electrode 2 by a vacuum evaporation method with a thickness of 20 nm using a metal mask having an opening of 120 mm × 100 mm, and thereafter an aluminum film is used using a metal mask having an opening of 124 mm × 104 mm. The nickel oxide film (hole transport layer 3) was formed to a thickness of 150 nm so as to cover the entire surface.

  Thereafter, using a glass plate as a sealing material, it was placed so as to cover the entire light emitting region, and the adhesive was thermally cured at about 90 ° C. for 1 hour for sealing. When the active matrix driving type organic EL display device 100 thus obtained was driven, it was in a uniform light emitting state with no luminance unevenness.

  Before the hole transport layer 3 was formed, it was produced in the same procedure as in Example 1, and molybdenum oxide was patterned as a hole transport layer 2 with a thickness of 80 nm by a shadow mask method using a vacuum deposition method. The pattern region was formed using a metal mask having an opening of 120 mm × 100 mm so as to be formed on the entire display region. Thereafter, the interlayer layer 16 and the organic light emitting layer 17 were produced in the same procedure as in Example 1.

  Thereafter, a calcium film is formed as a counter electrode 2 by a vacuum evaporation method with a thickness of 20 nm using a metal mask having an opening of 120 mm × 100 mm, and thereafter an aluminum film is used using a metal mask having an opening of 124 mm × 104 mm. The molybdenum oxide film (hole transport layer 3) was formed to a thickness of 80 nm so as to cover the entire surface.

  Thereafter, in the same manner as in Example 1, a glass plate was used as a sealing material so as to cover the entire light emitting region, and the adhesive was thermally cured at about 90 ° C. for 1 hour for sealing. When the active matrix driving type organic EL display device 100 thus obtained was driven, it was in a uniform light emitting state with no luminance unevenness.

(Comparative Example 1)
Before the hole transport layer 3 was formed, the film was produced in the same procedure as in Example 1. As the hole transport layer 3, molybdenum oxide was patterned into a film with a thickness of 50 nm by the shadow vapor deposition method by the vacuum evaporation method. The pattern region was formed using a metal mask having an opening of 120 mm × 100 mm so as to be formed on the entire display region. Thereafter, the interlayer layer 16 and the organic light emitting layer 17 were produced in the same procedure as in Example 1.

  Thereafter, a calcium film is formed as a counter electrode 2 by a vacuum vapor deposition method to a thickness of 20 nm using a metal mask having an opening of 120 mm × 100 mm, and then an aluminum film is thickened using a metal mask having an opening of 120 mm × 100 mm. The film was formed at 150 nm.

  Thereafter, in the same manner as in Example 1, a glass plate was used as a sealing material so as to cover the entire light emitting region, and the adhesive was thermally cured at about 90 ° C. for 1 hour for sealing. When the active matrix driving type organic EL display device 100 thus obtained was driven, it was in a uniform light emitting state with no luminance unevenness.

(Comparative Example 2)
Before the hole transport layer 3 was formed, the film was produced in the same procedure as in Example 1. As the hole transport layer 3, molybdenum oxide was patterned into a film with a thickness of 50 nm by the shadow vapor deposition method by the vacuum evaporation method. The pattern region was formed using a metal mask having an opening of 120 mm × 100 mm so as to be formed on the entire display region. Thereafter, the interlayer layer 16 and the organic light emitting layer 17 were produced in the same procedure as in Example 1.

  After that, an opening of 118 mm × 90 mm as a counter electrode 2 by a vacuum vapor deposition method and an opening of a pattern for contacting the 10 mm □ TFT substrate 5 and the counter electrode 2 above and below two sides of the 90 mm are the above openings. A film was formed with a thickness of 20 nm using a continuous metal mask. Thereafter, an aluminum film having a thickness of 150 nm was formed using the same metal mask. By using this metal mask, the counter electrode 2 is formed inside the molybdenum oxide (hole transport layer 3) pattern region except for the contact portion.

  Thereafter, in the same manner as in Example 1, a glass plate was used as a sealing material so as to cover the entire light emitting region, and the adhesive was thermally cured at about 90 ° C. for 1 hour for sealing. When the active matrix driving type organic EL display device 100 thus obtained was driven, it was in a uniform light emitting state with no luminance unevenness.

  Thereafter, the samples of Examples 1, 2, and 3 and Comparative Examples 1 and 2 were subjected to a constant temperature and humidity test. When an acceleration test was performed in an environment of 60 ° C. and 90%, no dark spots were observed even after 1000 hours in Examples 1, 2 and 3, but in Comparative Examples 1 and 2, the display area was Dark spots began to increase from the outside.

  By forming a film so that the entire surface of the inorganic layer is covered with the counter electrode 2, the surface and the end of the inorganic layer do not react with oxygen and moisture 27, so that no dark spots are generated, and there is no display defect. 100 could be obtained.

  Furthermore, by making the thickness of the counter electrode 2 equal to or thicker than the thickness of the inorganic layer, the entire surface of the inorganic layer can be covered with the material of the counter electrode 2 at the end of the pattern, and the durability of the organic EL display device 100 is improved. Will improve.

1 is a schematic cross-sectional view of an organic EL display device according to an embodiment of the present invention. 1 is a schematic top view of an active matrix drive organic EL display device according to an embodiment of the present invention. 1 is a schematic top view of a passive matrix drive organic EL display device according to an embodiment of the present invention. (A) And (b) is a schematic sectional drawing which shows the edge part of the organic electroluminescence display which concerns on embodiment of this invention. 1 is a schematic sectional view of a relief printing apparatus according to an embodiment of the present invention. It is a schematic top view of a conventional organic EL display device. It is a schematic sectional drawing which shows the edge part of the conventional organic electroluminescence display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display region 2 Counter electrode 3 Hole transport layer 4 including an inorganic layer Display device 5 Substrate 6 Active layer 7 Gate insulating film 8 Gate electrode 9 Interlayer insulating film 10 Drain electrode 11 Scan line 12 Source electrode 13 Pixel electrode 14 Partition 16 Inter Layer layer 17 Organic light emitting layer 19 Ink tank 20 Ink chamber 21 Anilox roll 211 Ink layer 22 Plate 23 Plate cylinder 24 Print substrate 25 Flat base 26 Organic light emitting medium layer 27 Oxygen and moisture 30 Display area 31 Pixel electrode 32 Counter electrode 33 Inorganic layer Hole transport layer 34 containing display device 36 organic light emitting layer 37 oxygen or moisture 100 active matrix drive organic EL display device 200 passive matrix drive organic EL display device 300 letterpress printing device 400 conventional active matrix drive organic EL display device

Claims (11)

A substrate,
A plurality of first electrodes formed on the substrate;
A plurality of partition walls partitioning the first electrode into different pixels;
A hole transport layer including an inorganic layer formed on the first electrode;
An organic light emitting layer formed on the hole transport layer;
A second electrode covering the entire surface of the hole transport layer formed on the organic light emitting layer;
An organic EL display device comprising:   The organic EL display device according to claim 1, wherein the second electrode has a thickness of 80 nm or more.   The organic EL display device according to claim 1, wherein a film thickness of the second electrode is equal to or thicker than a film thickness of the inorganic layer.   4. The organic EL display device according to claim 1, wherein the material of the inorganic layer is a metal oxide.   5. The organic EL display device according to claim 1, wherein a height of the partition wall is 0.1 μm or more and 10 μm or less. Prepare the board
Forming a plurality of first electrodes on the substrate;
Forming a plurality of barrier ribs so as to partition the first electrode into different pixels;
Forming a hole transport layer including an inorganic layer on the first electrode;
Forming an organic light emitting layer on the hole transport layer;
A method of manufacturing an organic EL display device, comprising: forming a second electrode on the organic light emitting layer so as to cover the entire surface of the hole transport layer.   The method of manufacturing an organic EL display device according to claim 6, wherein the film thickness of the second electrode is 80 nm or more.   8. The method of manufacturing an organic EL display device according to claim 6, wherein a film thickness of the second electrode is equal to or thicker than a film thickness of the inorganic layer.   9. The method for manufacturing an organic EL display device according to claim 6, wherein the material of the inorganic layer is a metal oxide.   The method for manufacturing an organic EL display device according to claim 6, wherein a height of the partition wall is 0.1 μm or more and 10 μm or less.   The one or more of the first electrode, the partition, the hole transport layer, the organic light emitting layer, and the second electrode are formed using a wet film forming method. The manufacturing method of the organic electroluminescence display in any one.

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